Electromagnetic switch



April 1942- l. w. cox 2,280,893

ELECTROMAGNETIC. SWITCH Filed Nov. 50, 1939 Load 82' Load 83 INVENTOR ATTORNEYS.

Patented Apr. 28, 1942 2,280,893 ELECTROMAGNETIC SWITCH Irvin W. Cox,

Milwaukee, Wis., assignor to Associated Electric Laboratories, Inc., Chicago, 111., a corporation of Delaware Application November 30, 1939, Serial No. 306,802

13 Claims.

comprise two separate and distinct units arranged in cooperating relationship.

Accordingly, it is an object of the present invention to provide an automatic switch of the hermetically sealed type which includes improved and unitary switching and operating structure.

Another object of the invention is to provide an improved automatic switch of the magnetic type comprising common magnetic circuit and electric circuit elements.

Another object of the invention is to provide an improved automatic switch which is of extremely simple and rugged construction, which is compact and economical to manufacture and which is efiicient in operation.

A further object of the invention is to provide an improved automatic switch for converting steady direct current into pulsating direct current.

A further object of the invention is to provide in combination with an automatic switch an improved electric circuit network for controlling the operation of the switch.

In the illustrated embodiment of the invention there is provided an automatic switch operative to convert steady direct current into pulsating direct current which comprises a resilient magnetic diaphragm, first and second magnetic substantially cup-shaped yokes respectively associated with opposite sides of the diaphragm to provide an enclosing casing, and an arrangement including a nonmagnetic ring mutually associated with the yokes for retaining the yokes in assembled relation and for clamping the diaphragm between the yokes. First and second substantially cup-shaped nonmagnetic housing elements are respectively sealed to opposite sides of the diaphragm by fused metal, and first and second magnetic pole pieces respectively carried by the first and second yokes respectively extend through openings provided in the first and second housing elements and are respectively sealed to the first and second housing elements, thereby to provide first and second hermetically sealed chambers respectively, disposed between the diaphragm and the first and second housing elements. First and second magnetic armature pieces are carried by the diaphragm and respectively arranged in the first and second chambers, the first and second armature pieces being respectively associated in spaced relation with the first and second pole pieces. The first pole piece, the first armature piece, the diaphragm and the first yoke are arranged in a first magnetic circuit; while the second pole piece, the second armature piece, the diaphragm and the second yoke are arranged in a second magnetic circuit. An arrangement including first and second windings respectively carried by the first and second pole pieces is provided for causing vibration of the armature, whereby the first and second armature pieces are moved alternately respectively into engagement with the first and second pole pieces. Furthermore, the first and second armature pieces and the diaphragm are mutually electrically connected together; while the first and second pole pieces and the first and second yokes are respectively electrically connected together. Finally, the first and second pole pieces and the first and second housing elements are respectively insulated from each other; while the diaphragm and the first and second yokes are mutually electrically insulated from each other. Further, the switch comprises first and second circuit terminals respectively electrically connected to the first and second yokes, and a common circuit terminal electrically connected to the diaphragm.

An arrangement comprising a first member mutually associated with the first yoke and the first pole piece is provided for adjusting the position of the first pole piece with respect to the first yoke, thereby to adjust the distance between the first pole piece and the first armature piece; while an arrangement including a second member mutually associated with the second yoke and the second pole piece is provided for adjusting the position of the second pole piece with respect to the second yoke, thereby to. adjust the distance between the second pole piece and the second armature piece. The first and second armature pieces respectively positioned on opposite sides of the diaphragm are retained in place by an arrangement including a member extending through aligned openings provided in the diaphragm and in the first and second armature pieces. In order to minimize pitting between the first pole piece and the first armature piece and between the second pole piece and the second armature piece, an arrangement is provided which comprises copper caps, each enclosing at least a portion of the assoswitching unit I provided in the bottom wall ciated piece and constituting a contact form of are resistant material.

A circuit network is associated with the switch which comprises a source of circuit current, a start switch operative to complete and then to interrupt a circuit, a start circuit for energizing the second winding including the source of supply and the start switch, an operating circuit for energizing the first winding including a source of supply and the second. circuit terminal and the common circuit terminal, and an operating circuit for energizing the second winding including the source of supply and the first circuit terminal and the common circuit terminal. Further, the circuit network comprises a first loadv circuit including the source of supply and the first circuit terminal and the common circuit terminal, and a second load circuit including the source of supply and the second circuit terminal and the common circuit terminal.

Further features of the invention pertain to the particular construction and arrangement of the elements of the automatic switch, whereby the above-outlined and additional operating features are attained.

The novel features believed to be characteristic of the invention are set forth with partioularity in the appended claims. The invention, both as to its organization and method of operation, together with further objects and advantages thereof, will best be understood by reference to the following specification taken in connection with the accompanying drawing in which Figure 1 is a longitudinal sectional view of a sealed switch and a diagrammatic illustration of an operating circuit therefor embodying the present invention; and Fig. 2 is. a fragmentary plan view of the switch, illustrating the arrangement for securing in place one of the pole pieces thereof.

Referring now more particularly to the drawing there is illustrated a sealed switch embodying the features of the present invention and I comprising a sealed switching unit I and complementary casing yokes II and I2. The sealed I0 comprises a vibratory diaphragm I3, complementary housing elements II and I disposed 'on opposite sides of the diaphragm I3, an armature I6 and two pole pieces I1 and I8. The housing element It is substantially cup shaped and includes a substantially flat bottom wall I9, a cylindrical side wall 20 and an annular flange 2I; while the housing element I5 is substantially cup shaped and includes a substantially flat bottom wall 22, a cylindrical side wall 23 and an annular flange 24. The annular flanges 2| and 24, respectively, of the housing elements It and I5 are disposed in contacting relationship with the opposite sides of the diaphragm I3 adjacent the periphery thereof and are line welded thereto in order to provide hermetic seals between the diaphragm I3 and the respective housing elements I4 and I5.

The pole piece I! includes a head 25 arranged within the switching unit It and disposed between the diaphragm I3 and the bottom wall I9 of the housing element I4 and a shank 26 extending through a centrally located opening provided in the bottom wall I9 of the housing element I 4; similarly, the pole piece I8 includes a head 21 arranged'within the switching unit I 0 and disposed between the diaphragm I3 and the bottom wall 22 of the housing element I5 and a shank 28 extending through a centrally located opening 22 of the housing element I5. A sleeve 29 is disposed about the shank 26 of the pole piece II adjacent, the head 25 thereof and welded thereto; similarly, a sleeve 30 is disposed about the shank 28 of the pole piece I8 adjacent the head 21 thereof and welded thereto. Also an annularring Ma is disposed within the opening located in the bottom wall I9 of the housing element I4 and welded inplace therein; similarly, an annular ring I5a is disposed within the opening located in the bottom wall 22 of the housing element I5 and welded in place therein. The sleeve 29 carried by the shank 26 of the pole piece 51 is arranged within an opening provided in the annular ring Ma and sealed thereto by a ring of glass 3I; similarly, the sleeve 30 carried by the shank 28 of the pole piece I8 is arranged within an opening provided in the annular ring I5a and sealed thereto by a ring of glass 32.

In order to eliminate internal strains in the glass sealor ring 3I between the metal sleeve 29 and the metal ring Ida these parts areformed of materials having thermal expansion characteristics which closely match one another throughout the temperature range between 0 C. and the softening temperature of the glass ring 3|. This result may be accomplished by forming the sleeve 29 and the ring Ha of material comprising an alloy essentially of iron, nickel and cobalt and by forming the glass ring 3| of a material comprising boro-silicate glass, as described in U. S. Patent No. 2,071,196, Burger et al., issued February 16, 1937. For example, a glass having the approximate composition of 65% silica (SiOz), 23% boric oxide (B203) 7% sodium oxide (NazO) and 5% aluminum oxide (A1203) may be fused to an alloy having the approximate composition of 18% cobalt (Co), 28% nickel v(Ni), and 54% iron (Fe) in order to provide a seal therebetween which is free'of internal strains. Other examples of suitable glasses and alloys which may be utilized to provide seals free of internal strains are described in the above-mentioned Burger et a1. patent.

In a similar manner the I5a are formed of the glass ring 32 is formed order to eliminate internal strains in the glass seal or ring 32 between the metal sleeve 30 and the metal ring I5a.

, Further the sealed switching unit vided with a seal-oil tube 33 arranged in an opening provided in the bottom wall 22 of the housing element I5 and having a flanged head 34 welded to the inner surface of the bottom wall 22 of the housing element I5. Further it is noted that an opening 35 is provided in the diaphragm I3 in order to afford communication between the two chambers disposed on sleeve 30 and the ring by the diaphragm I3 and the housing elements I4 and I5, Finally it is noted that the two chambers provided on the opposite sides of the diaphragm I3 are evacuated by way of the seal-off tube 33 and that the wall of the seal-off tube 33 is then pinched and welded adjacent the outer end thereof in order completely and hermetically to seal the switching unit I II.

The armature I6 comprises complementary armature pieces 36 and 31 disposed on opposite sides of the diaphragm I3 and a rivet 38 extending through aligned openings provided in the diaphragm I3 and the respective armature pieces 36 and 31. The diaphragm -I3, the armature pieces 36 and 31, the pole pieces I? and I3 and alloy mentioned, while the of the glass mentioned in I0 is proopposite sides thereof the casing yokes I] and II are formed of magnetic material, such, for example, as mild steel, as these elements are included in magnetic circuits traced hereinafter; while the housing elements l4 and I5 are formed of a resilient nonmagnetic material such as brass. The armature pieces 36 and 31 and the pole pieces i1 and I8 are included in electric circuits traced hereinafter, the armature piece 38 and the head 25 of the pole piece l1 constituting a switch in one of these electric circuits and the armature piece 31 and the head 21 of the pole piece l8 constituting a switch in another of these electric circuits. Accordingly the armature pieces 36 and 31 and the heads 25 and 21 of the respective pole pieces l1 and l8 are provided with copper caps in order to minimize pitting incident to interruption of the electric circuits. More particularly, the armature pieces 36 and 31 are respectively provided with cup-shaped copper caps 39 and 40 securely fastened thereto; while the heads 25 and 21 of the respective pole pieces l1 and I8 are respectively provided with dish-shaped copper caps 4| and 42 securely fastened thereto. The casing yoke I is substantially cup shape and includes a substantially flat bottom wall 43, a cylindrical side wall 44 and an annular flange 45; similarly the casing yoke I2 is substantially cup shaped and includes a substantially flat bottom wall 45, a cylindrical side wall 41 and an annular flange 48. The casing yokes II and I2 are retained in assembled relationship and the sealed switching unit H1 is securely positioned between the pole piece I1 and retained in place by two spaced-apart insulating heads 59 and GI; similarly a winding 52 is provided about the shank 28 of the pole piece l8 and retained in place by two spaced-apart insulating heads 53 and 54. The

the annular flanges and 48, respectively carried by the casing yokes H and I2, by an arrangement including a ring 49 provided with an annular flange 50 cooperating with the annular flange 45 carried by the casing yoke H and a threaded portion cooperating with a thread provided on the outer surfaceof the annular flange 48 carried by the casing yoke l2. The ring 49 is formed of nonmagnetic material, such, for ex ample, as brass and is threaded onto the threaded annular flange 48 carried by the casing yoke l2 in order to force the annular flanges 45 and 48, respectively carried by the casing yokes"|| and I2, into clamped engagement with the annular flanges 2| and 24 respectively carried by the housing elements l4 and I5 of the sealed switching unit -.|0. At this point it is noted that the ring 49 is electrically insulated from the casing yoke II and the sealed switching unit ID by an insulating washer 5| formed of rubber or the like disposed therebetween. Also the flanges 2| and 24 respectively carried by the housing elements l4 and iii of the sealed switching units III are electrically insulated from the flanges 45 and 48 respectively carried by the casing yokes H and i2 and from the ring 49 by an insulating washer -52 formed of rubber or the like and having a substantially U-shaped cross-section.

The outer end of the pole piece H is threaded, as indicated at 53, and extends through a centrally located opening provided in the bottom wall 43 of the casing yoke |l; similarly, the outer end of the pole piece I8 is threaded, as indicated at 54, andextends through a centrally located opening provided in the bottomwall 4B of the casing yoke l2. An arrangement including a spanner nut 55 and a bracket nut 56 threaded on the outer end of the pole piece l1 isprovided for adjustably securing the pole piece H to the bottom wall 43 of the casing yoke ll; similarly an arrangement" including a spanner nut- 51 and a bracket nut 58 threaded on the outer end of the two terminals of the winding 59 are electrically connected to two insulated terminal blocks 55 and 66 carried by the bottom wall 43 of the casing yoke while the two terminals of the winding 52 are electrically connected to two insulated terminal blocks 61 and 88 carried by the bottom wall 46 of the casing yoke i2. Further, it is noted that the sealed switching unit I0 is electrically connected by a conductor 59 to an insulated terminal block 18 carried by the bottom wall 43 of the casing yoke Finally two electrical terminals 1| and 12 are respectively carried directly by the cylindrical side walls '44 and 41 of the casing yokes II and I2, respectively.

A circuit network is associated with the sealed switch which comprises a source of direct current supply, such as a battery 80, a control switch S8l,

wo loads 82 and 83, two line switches S84 and S85, and a number of conductors connected and arranged in a manner more fully described hereinafter.

Before proceeding with the mode of operation of the sealed switch and the use of the sealed switch to control the supply of pulsing current to the loads 82 and 83, it is noted that the distance between the contacts afforded by the copper caps 39 and 4| respectively secured to the armature piece 38 and the head 25 oi the pole piece l1 may be adjusted by means of the spanner nut 55 and the bracket nut 56; similarly, the distance between the contacts afforded by the copper caps 4| and 42 respectively secured to the armature piece 31 and the head 21 of the pole piece |8 may be adjusted by means of the spanner nut 51 and the bracket nut 58. For example, in

order to adjust the position of the'pole piece l1 with respect to the armature |8 and consequently the distance between the copper cap 4| secured to the head 25 of the pole piece I1 and the copper cap 39 secured to the armature piece 31, it is only necessary to loosen the spanner nut 55 and then adjust the bracket nut 55 in the proper direction. After the bracket nut 58 has been adjusted in the proper direction the spanner nut 55 is again tightened in order securely to lock the pole piece ii in its adjusted position with respect to the casing yoke ii. It is noted that when the spanner nut 55 is loosened the pole piece l1 may be moved in one direction with respect to the armature It by rotating the bracket nut 56 in a corresponding direction; similarly, at this time, the pole piece il may be moved in the opposite direction with respect to the armature It by rotating the bracket nut 58 in a corresponding direction.

During the operation of the sealed switch the diaphragm i3 and the armature l6 vibrate in order to cause the cooperating copper caps 39, 4i and 48, 42 to be moved into alternate engagements. When the armature I6 is moved toward the pole piece i1 and away from the pole piece l8 the copper caps 39 and 4| are moved into contact, while the copper caps 40 and 42 are moved out 0! tween the terminals 18 and H, the conductor C9I being connected to the terminal 'llland the conductors C98 and CIIlIl being connected to the terminal 1 I. On the other hand, when the copper caps 48 and 42 are respectively moved into contact and out of contact an electric circuit is respectively completed and interrupted between the terminals 18 and 12, the conductor C9I being connected to the terminal 16 and the conductors C99 and CIIII being connected to the terminal 12.

In assembling the sealed switch the sealed switching unit I is first assembled and the casing yokes II and I2 are then assembled thereon. More particularly, the armature pieces 36 and 31 are first secured to the diaphragm I3 by the rivet 38 and then the copper caps 39 and 48 are respectively secured to the armature pieces 36 and 31. The copper caps 4I and 42 are respectively secured to the heads 25 and 21 of the pole pieces I1 and I8, respectively; and then the sleeves 29 and 38 are respectively welded to the shanks 26 and 28 of the pole pieces I1 and I8, respectively. The annular rings Ma and Ia are 'welded in the openings located in the bottom walls of the hous ing elements I4 and I5, respectively. The pole piece I1 is then inserted through the opening provided in the ring I41: and sealed in place by the glass ring 3I; similarly, the pole piece I8 is then inserted through the opening provided in the ring I5a and sealed in place by the glass ring 32. The flanges .2I and 24 respectively carried by the housing elements I4 and I5 are then brought into engagement with the opposite sides of the diaphragm I3 adjacent the periphery thereof and line welded thereto.

The chambers disposed on opposite sides of the diaphragm I3 are then evacuated by way of the seal-off tube 33, whereupon the wall of the seal-off tube 33 is pinched and welded in order hermetically to seal the switching unit In. It is noted that when the chambers disposed on opposite sides of the-diaphragm I3 are evacuated the bottom walls I9 and 22 of the housing elements I4 and I5 respectively are collapsed due to atmospheric pressure, thereby to move the pole pieces I] and I8 into engagements with the armature I6. More particularly, at this time, the copper caps 39, 49 and 40, 42 are forced into engagements due to atmospheric pressure.

The spanner nuts 55 and 51 are then threaded upon the shanks 26 and 28 of the pole pieces I1 and I8, respectively, and the casing yokes II and I2 are then brought into position with respect to the sealed switching unit II). Th ring 49 is then brought into place and screwed into position in order securely to retain the sealed switching unit I8 between the flanges 45 and 48 respectively carried by the casing yokes II and I2 after the terminals of the windings 59 and 62 and the conductor 69 welded to the housing element I4 have been electrically connected to the respective terminal blocks carried by the bottom walls of the casing yokes II and I2. The bracket nuts 56 and 58 are threaded on the ends of the shanks 26 and 28 of the respectiv pole pieces I1 and I8 and rotated in order to move the pole pieces I1 and I8, respectively, away from the armature I 6 and until the copper caps 4i and 42 respectively secured to the heads 25 and 21 of the pole pieces I1 and I6, respectively, are moved out of engagements with the copper caps 39 and 40 respectively secured to the armature pieces 36 and 31, thereby to adjust the distances between the copper caps 39, ll and 48, 42. After the distances between the copper caps 39, ll and 48, 42 have been adjusted, the spanner nuts 55 and 51 are rotated in order positively to lock the pole pieces I1 and I8, respectively, in their ad-' justed positions with-respect to the casing yokes II and I2, respectively. The terminal blocks 65, 66, 61, 68 and 10 and the terminals II and 12 carried by the sealed switch are connected in the external circuit in a manner more 'fully described hereinafter.

Operation of the sealed switch is initiated by depressing the control switch S8I, thereby to cause the contacts 86 and 88 thereof to be actuated into engagement immediately and the contacts 81 thereof to be actuated into disengagement subsequently. When the contacts 86 of the control switch S8I are actuated into engagement a start circuit is completed for energizing the winding 62 carried by the shank 28 of the pole piece I8, this circuit extending from the positive terminal of the battery by way of the conductor C96, the terminal block 68. the winding 62,

the terminal block 61, the conductor C94, the

contacts 81 and 86 of the control switch SM and the conductor C96 to the negative terminal of the battery 80. When the winding 62 is thus energized a flux is produced in the pole piece I8,

thereby to cause the armature I6 to be moved toward the pole piece I8. The flux produced in the pole piece I8 traverses a path extending from the head 21 of the pole piece I8 by way of the armature piece 31, the diaphragm I3, the casing yoke I2 and the spanner nut 51 to the shank 28 of the pole piece I8. Subsequently, when the contacts 81 of the control switch S8I are actuated into disengagement the previously traced circuit for energizing the winding 62 is inter- I rupted.

Whenthe armature I6 moves toward the pole piece I8 the copper caps 40 and 42 are moved into contact, whereupon an operating circuit is completed for energizingthe winding 59 carried by the pole piece I1, this circuit extending from the positive terminal of the battery 80 by way of the conductor C91, the terminal block 66, the winding 59, the terminal block 65, the conductor CIOI, the terminal 12, the casing yoke I2, the spanner nut 51, the pole piece I8, the copper caps 42 and 48, the armature piece 31, the diaphragm I3; the housing element I4, the conductor 69, the terminal block 16, the conductor C9I, the contacts 88 of the control switch S8I and the conductor C90 to the negative terminal of the battery 86. When the winding 59 is thus energized a flux is produced in th pole piece I1 which causes the armature I6 to be moved toward the pole piece I1. The flux produced in the pole piece I1 traverses a path extending from the head 25 of the pole piece I1-by way of'the armature piece 36, the diaphragm I3, the casing yoke II and the spanner nut 55 to the shank 26 of the pole piece I1. More particularly, the armature I6 moves away from the pole piece I8 and toward the pole piece I1, thereby to cause. the copper caps 48 and 42 to be moved out of contact and to cause the copper caps 39 and 4| to be moved into contact.

89!, the conductor C9l, the terminal block 19,-

When the copper caps 49 and 42 are moved out 7 of contact the previously traced circuit for energizing the winding 59 carried by the pole piece I1 is interrupted; and when the copper caps 39 and 4| are moved into contact an operating circuit is completed for energizing the winding 62 carried by the pole piece l9. The operating circult for energizing the winding 62 carried by the pole piec l8 extends from the positive terminal of the battery 99 by way of the conductor C96, the terminal block 69, the winding 62, the terminal block 61, the conductor C99, the terminal H, the casing yoke II, the spanner nut 55, the

pole piece II, the copper caps 4i and 39, the

armature piece 36, the diaphragm IS, the housing element 14, the conductor 69, the terminal block 10, the conductor 091, the contacts as of the control switch SM and the conductor C99 to the negative terminal of the battery 99.

When the winding 62 carried by the pole piece [9 is thus energized flux is produced in the pole piece I8 which causes the armature IE to move away from the pole piece I! and toward the pole piece l9. More particularly, the movement of the armature l6 causes the copper caps 39 and 4| to. be moved, out of contact and the copper caps 49 and 42 to be moved into contact. When the copper caps 39 and 4! are moved out of contact the previously traced operating circuit for energizing the winding 62 carried by the pole piece I8 is interrupted; and when the copper caps 49 and 42 are moved into contact the previously traced operating circuit for energizing the winding 59 carried by the pole piece I1 is completed.

In view of the above description it will be un derstood that the armature l6 vibrates between the pole pieces i1 and 19, thereby to cause the previously traced operating circuits for energizing the windings 59' and 62 respectively carried by the pole pieces I! and I9 to be completed alternatively, which alternative completion of the circuits for energizing the windings 59 and 62 cause the armature l6 to vibrate between the pole pieces I! and I8 in the manner previously described. At this point it is noted that the armature l6 vibrates between the pole pieces I1 and I8 at a predetermined frequency determined by the natural frequency of vibration of the moving system including the diaphragm l3 and the armature IS. The natural frequency of vibration of the moving systemis determined primarily by the mass of the armature l6 and the diaphragm l3 and by the stiffness of the diaphragm I3. By controlling the mass of the armature I6 and .the diaphragm l3 and the stiffness of the diaphragm l3 incident to the design of the sealed switch, the frequency of vibration of the armature l6 between the pole pieces 11 and I9 may be predetermined within a relatively wide frequency band.

The supply of pulsating current to the load 92,

9 while the sealed switch is operating in the manterminal of the battery 99 by way of the con-' ductor C99, the contacts 99 of the control switch the conductor 69, the housing element l4, the diaphragm i3 and the armature piece 31 to the copper cap 49. This prepared circuit is completed and interrupted respectively each time the copper cap 49 is moved respectively into engagement and disengagement with the copper cap 42, thereby to cause pulsating current to be 1 supplied to the load 92.

The supply of pulsating current to the load 93, while the sealed switch is operating in the manner described above, may be controlled by the line switch S95. More particularly, when the line switch S is closeda circuit is prepared for supplying pulsating current from the battery 89 to the load 93, this circuit extending from the positive terminal of the battery 99 by way of the conductor C93, the load 83, the line switch $95, the conductor Cl99, the terminal II, the casing yoke ll, the spanner nut 55 and the pole piece I! to the copper cap 4|, and from the negative terminal or the battery 89 by way of the conductor C99, the contacts 89 of the control switch S9l, the conductor C9 i, the terminal block 19, the conductor 69, the housing element I4, the diaphragm l3 and the armature piece 36 to the copper cap 39. This prepared circuit is completed and interrupted, respectively, each time the copper cap 39 is moved respectively into engagement and disengagement with the copper cap 4|, thereby to cause pulsating current to be supplied to the load 93.

In view of the above description of the mode of operation of the sealed switch it will be understood that operation of the sealed switch is initiated when the control switch S8! is depressed and operation of the sealed switch is arrested when the control switch SBI is released. Further it will be understood that while the sealed switch is operating the supply of pulsating current from the battery 89 to the loads 82 and 93 may be selectively controlled by the line switches S94 and S95. Finally it is noted that when the sealed switch is operating and both of the line switches S94 and S95 are closed pulsating current is alternatively supplied to the loads 82 and 93.

While there has been described what is at present considered to be the preferred embodiment of the invention, it will be understood that various modifications may be made therein, and it is contemplated to cover in the appended claims all such modifications as fall within the true spirit and scope of the invention.

What is claimed is:

1. A switch comprising a resilient magnetic diaphragm, a substantially cup-shaped nonmagnetic housing element sealed to one side of said diaphragm, a magnetic yoke associated with said diaphragm, a magnetic pole piece carried by said yoke, said pole piece extending through an opening provided in said housing element and sealed thereto, thereby to provide an hermetically sealed chamber disposed between said diaphragm and said housing element, a magnetic armature carried by said diaphragm and arranged in said chamber, said armature being associated in spaced relation with said pole piece, said pole piece and said armature and said diaphragm and said yoke being arranged in a magnetic circuit, a winding coupled to said magnetic circuit said diaphragm accommodating movement of said armature alternately into engagement and diselectrically connected together, said diaphragm and saidyoke being electrically insulated from each other, said pole piece and said housing element being electrically insulated from each other, a first circuit terminal electrically connected to said yoke, and a second circuit terminal electrically connected to said diaphragm,

2. A switch comprising a resilient magnetic diaphragm, a substantially cup-shaped nonmagpiece and said armature and said diaphragm being arranged in a magnetic circuit, a winding coupled to said magnetic circuit, said diaphragm accommodating movement of said second contact alternately into engagement and disengagement with said first contact, said armature and chamber disposed between said diaphragm and said housing element, a magnetic armature carried by said diaphragm and arranged in said chamber, said armature being associated in spaced relation with said pole piece, said pole piece and said armature and-said diaphragm and said yoke being arranged in a magnetic circuit, a winding coupled to said magnetic circuit, said diaphragm accommodating movement of said armature alternately into engagement and disengagement with said pole piece, said armature and said diaphragm being electrically connected together, said pole piece and said yoke being electri cally connected together, said diaphragm and said yoke being electrically insulated from each other, said pole'piece and said housing element being electrically insulated from each other, a first circuit terminal electrically connected to said yoke, and a second circuit terminal electrically connected to said diaphragm.

3. A switch comprising a resilient magnetic netic housing element sealed to one side of said diaphragm, a magnetic pole piece extending through an opening provided in said housing element and sealed thereto, thereby to provide an hermetically sealed chamber disposed between said diaphragm and said housing element, a magnetic armature carried by said diaphragm and arranged in said chamber, said armature being associated in spaced relation with said pole piece, said pole piece and said armature and said diaphragm being arranged in a magnetic circuit, a winding coupled to said magnetic circuit, said diaphragm accommodating movement of said armature alternately into engagement and disengagement with said pole piece, said armature and said diaphragm being electrically connected together, said pole piece and said housing element being electrically insulated 'from each other, a first circuit terminal electrically connected to said pole piece, and a second circuit terminal electrically connected to said diaphragm.

4. A switchcomprising a resilient magnetic diaphragm, a substantially cup-shaped nonmagnetic housing element sealed to one side of said diaphragm, a magnetic pole piece extending through an opening provided in said housing element and sealed thereto, thereby to provide an hermetically sealed chamber disposed between said diaphragm and said housing ele- -ment, a magnetic armature carried by said diaphragm and arranged in said chamber, said armature being associated in spaced relation with said pole'piece, a first contact carried by said ture, said first and second contacts being arranged in spaced relation within said chamber diaphragm, a substantially cup-shaped nonmagpole piece, a second contact carried by said armaand formed of arc-resistant material, said pole said diaphragm being electrically connected together, saidpole piece and said housing element being electrically insulated from each other, a first circuit terminal electrically connected to said pole piece, and a second circuit terminal electrically connected to said diaphragm.

5. A switch comprising a resilient magnetic diaphragm, a substantially cup-shaped nonmagnetic housing element sealed to one side of said diaphragm by fused metal, a magnetic pole piece extending through an opening provided in said housing element and sealed thereto by fused glass, thereby to provide an hermetically sealed chamber disposed between said diaphragm and said housing element, said chamber being partially evacuated, a magnetic armature carried by said diaphragm and arranged in said chamber, said armature being associated in spaced relation with said pole piece, said pole piece and said armature and said diaphragm being arranged in a magnetic circuit, a winding coupled to said magnetic circuit, said diaphragm accommodating movement of said armature alternately into engagement and disengagement with said pole piece, said armature and said diaphragm being electrically connected together, said pole piece and said housing element being electrically insulated from each other, a first circuit terminal electrically connected to said pole piece, and a second circuit terminal electrically connected to said diaphragm.

6. A switch comprising a resilient magnetic diaphragm, a substantially cup-shaped nonmagnetic housing element sealed to one side of said diaphragm, ,a magnetic pole piece extending through an opening provided in said housing element and sealed thereto, thereby to provide an hermetically sealed chamber disposed between said diaphragm and said housing element, a magnetic armature carried by said diaphragm and arranged in said chamber, said armature being associated in spaced relation with said pole piece, a first cap enclosing at least a portion of said pole piece, a second cap enclosing at least a portion of said armature, said first and second caps respectively constituting first and second. contacts arranged in spaced relation within said chamber and formed of arcresistant material, said pole piece and said armature and said diaphragm being arranged in a magnetic circuit, a winding coupled to said magnetic circuit, said diaph ragm accommodating movement of said second contact alternately into engagement and disengagement with said first contact, said armature and said diaphragm sealed chamber disposed between said diaphragm and said housing element, a magnetic armature carried by said diaphragm and arranged in said chamber, said armature being associated in spaced relation with said pole piece, means including a member mutually associated with said yoke and said pole piece for adjusting the position of said pole piece with respect to said yoke,

' thereby to adjust the distance between said pole piece and said armature, said pole piece and said armature and said diaphragm and said yoke being arranged in a magnetic circuit, a winding coupled to said magnetic circuit, said diaphragm accommodating movement of said armature alternately into engagement and disengagement with said pole piece, said armature and said diaphragm being electrically connected together, said pole piece and said yoke being electrically connected together, said diaphragm and said yoke being electrically insulated from each other, said pole piece and said housing element being electrically insulated from each other, a first circuit terminal electrically connected to said yoke, and a second circuit terminal electrically connected to said diaphragm.

8. A switch comprising a resilient magnetic diaphragm, first and second substantially cupshaped nonmagnetic housing elements respectively sealed to opposite sides of said diaphragm, first and second magnetic yokes respectively associated with opposite sides of said diaphragm, first and second magnetic pole pieces respectively carried by said first and second yokes, said first and second pole pieces respectively extending through openings provided in said first and second housing elements and respectively sealed to said first and second housing elements, thereby to provide first and second hermetically sealed chambers respectively disposed between said diaphragm and said first and second housing elements, first and second magnetic armature pieces carried by said diaphragm and respectively arranged in said first and second chambers, said first and second armature pieces being respectively associated in spaced relation with said first and second pole pieces, said first pole piece and said first armature piece and said diaphragm and said first yoke being arranged in a first magnetic circuit, said second pole piece and said second armature piece and said diaphragm and said second yoke being arranged in a second magnetic circuit, first and second windings respectively coupled to said first and secondmagneticcircuits, said diaphragm accommodating movement of said armature alternately into engagement with said first and second pole pieces, said firstand second armature pieces and said diaphragm being mutually electrically connected together, said first and second pole pieces and said first and second yokes being respectively electrically connected together, said diaphragm and said first and second yokes being mutually electrically insulated from each other, said first and second pole pieces and said first and second housing elements being respectively insulated from each other, first and second circuit terminals respectively electrically connected to said first and second yokes, and a common circuit terminal electrically connected to said diaphragm.

9. 'A switch comprising a resilient magnetic diaphragm, first and second substantially cupshaped nonmagnetic housing elements respectively sealed to opposite sides of said diaphragm, first and second magnetic pole pieces respectively extending through openings provided in said first and second housing elements and respectively sealed to said first and second housing elements, thereby to provide first and second hermetically sealed chambers respectively disposed between said diaphragm and said first and second housing elements, first and second magnetic armature pieces carried by said diaphragm and respectively arranged in said first and second chambers, said first and second armature pieces being respectively associated in spaced relation with said first and second pole pieces, said first pole piece and said first armature piece and said diaphragm being arranged in a first magnetic circuit, said second pole piece and said second armature piece and said diaphragm being arranged in a second magnetic circuit, first and second windings respectively coupled to said first and second magnetic circuits, said armature accommodating movement of said first and second armature pieces alternately respectively into engagement with said first and second pole pieces, said first and second armature pieces and said diaphragm being mutually electrically connected together, said first and 'second pole pieces and said first-and second housing elements beingrespectively insulated from each other, first and second circuit terminals respectively electrically connected to said first and second pole pieces, and a common circuit terminal electrically connected to said diaphragm,

10. A switch comprising a resilient magnetic diaphragm, first and second substantially cupshaped nonmagnetic housing elements respectively sealed to opposite sides of said diaphragm, first and second magnetic pole pieces respectively extending through openings provided in said first and second housing elements and respectively sealed to said first and second housing elements, thereby to provide first and second hermetically sealed chambers respectively disposed betwen said diaphragm and said first and second housing elements, first and second magnetic armature pieces carried by said diaphragm and respectively arranged in said first and second chambers, said first and second armature pieces being respectively associated in spaced relation with said first and second pole pieces, first and second contacts respectively carried by said first and second pole pieces, third and fourth contacts respectively carried by said first and second armature pieces, said first and third contacts being arranged in spaced relation within said first chamber and said second and fourth contacts being arranged in spaced relation within said second chamber, each of said contacts being formed of arc-resistant material, said first pole piece and said first armature piece and said diaphragm being arranged in a first magnetic circuit, said second pole piece and said second armature piece and said diaphragm being arranged in a second magnetic circuit, first and second windings respectively coupled to said first and second magnetic circuits, said diaphragm accommodating movement of said third and fourth contacts alternately respectively into engagement with said first and second contacts, said first and second armature pieces and said diaphragm being mutually electrically connected together, said first and second pole pieces and said first and second housing elements being respectively insulated from each other, first and second circuit terminals respectively electrically connected to said first and second pole pieces,

and a common circuit terminal electrically connected to said diaphragm.

11. A switch comprising a resilient magnetic I diaphragm, first and second substantially cupshaped non-magnetic housing elements respectively sealed to opposite sides of said diaphragm, first and second magnetic pole pieces respectively extending through openings provided in said first and second housing elements and respectively sealed to said first and second housing elements, thereby to provide first and second hermetically sealed chambers respectively disposed between said diaphragm and said first and second housing elements, first and second magnetic armature pieces carried by said diaphragm and respectively arranged in said first and second chambers, said first and second armature pieces being respectively associated in spaced relation with said first and second pole pieces, first and second caps respectively enclosing at least portions of said first and second pole pieces, third and fourth caps respectively enclosing at least portions of said first and second armature pieces, said first and third caps respectively constituting first and third contacts arranged in spaced relation within said first chamber and said second and fourth caps respectively constituting second and fourth contacts arranged in spaced relation within said second chamber, each of said contacts being formed of arc-resistant material, said first pole piece and said first armature piece and. said diaphragm being arranged in a first magnetic circuit, said second pole piece and said second armature piece and said diaphragm being arranged in a second magnetic circuit, first and second windings respectively coupled to said first and second magnetic circuits, said diaphragm accommodating movement of said third and fourth contacts alternately respectively into engagement with said first and second contacts, said first and second armature pieces and said diaphragm being mutually electrically connected together, said first and second pole pieces andsaid first and second housing elements being respectively insulated from each other, first and second circuit terminals respectively electrically connected to said first and second pole pieces, and a common circuit terminal electrically connected to said diaphragm.

12. A switch comprising a resilient magnetic diaphragm, first and second substantially cupshaped nonmagnetic housing elements respectively sealed to opposite sides of said diaphragm, first and second magnetic yokes respectively associated with opposite sides of said diaphragm, first and second magnetic pole pieces respectively carried by said first and second yokes, said first and second pole pieces respectively extending through openings provided in said first and second housing elements and respectively sealed to said first and second housing elements, thereby to provide first and second hermetically sealed chambers respectively disposed between said diaphragm and said first and second housing elements, first and second magnetic armature pieces carried by said diaphragm and respectively arranged in said first and second chambers, said first and second armature pieces beingrespectively associated in spaced relation with said first and second pole pieces, means including a first member mutually associated with said first yoke and said first pole piece for adjusting the position of said first pole piece with respect to said first yoke, thereby to adjust the distance between said first pole piece and said first armature piece, means including a second member mutually associated with said second yoke and said second pole piece for adjusting the position of 'said'second pole piece with respect to saidsecond yoke, thereby to adjust the distance between said second pole piece andsaid second armature piece, said first pole piece and said first armature piece and said diaphragm and said first yoke being arranged in a first magnetic circuit, said second pole piece and said second armature piece and said diaphragm and said second yoke being arranged in a second magnetic circuit, first and second windings respectively coupled to said first and second magnetic circuits, said diaphragm accommodating movement of said first and second armature pieces alternately respectively into engagement with said first and second pole pieces, said first and second armature pieces and said diaphragm being mutually electrically connected together, said first and second pole pieces and said first and second housing elements being respectively insulated from each other, said first and second pole pieces and said first and second yokes being respectively electrically connected together, said yokes, and a common circuit terminal electrically connected to said diaphragm.

13. A switch comprising a resilient magnetic diaphragm, first and second substantially cupshaped non-magnetic housing elements respectively sealed to opposite sides of said diaphragm, first and second substantially cup-shaped magnetic yokes respectively associated with opposite sides of said diaphragm, means including a nonmagnetic member mutually associated with said yokes for retaining said yokes in assembled relation and for clamping said diaphragm between said yokes, first and second magnetic pole pieces respectively carried by said first and second yokes and respectively extending through openings provided in said first and second housing elements, said first and second pole pieces being respectively associated in spaced relation with the opposite sides of said diaphragm and respectively sealed to said first and second housing elements, thereby to provide first and second hermetically sealed chambers respectively disposed between said diaphragm and said first and second housing elements, said first pole piece and said diaphragm and said first yoke being arranged in a first magnetic circuit, said second pole pieceand said diaphragm and said second IRVIN W. COX. 

